Anchors and methods for securing suture to bone

ABSTRACT

A method for securing suture to bone comprises drilling a hole in a desired portion of bone at a desired procedural site, passing a strand of suture through a portion of soft tissue to be approximated to the portion of bone, and extending the free suture ends proximally from the soft tissue. The suture is loaded into an anchor implant. Using an inserter, on a distal end of which is attached the anchor implant, the anchor implant is manipulated into the bone hole. The suture is then tensioned to a desired level by pulling on the free suture ends, after the anchor implant is positioned in the bone hole. The free suture ends are wrapped about a suture cleat on an inserter handle once the desired tension level is achieved. A proximal anchor component is moved distally to engage with a distal anchor component to lock the anchor in place within the bone hole, and to lock the suture in place within the anchor. Then, the inserter is removed from the procedural site.

This application is a continuation under 35 U.S.C. 120 of commonlyassigned U.S. patent application Ser. No. 12/485,878, entitled Anchorsand Methods fir Securing Suture to Bone, filed on Jun. 16, 2009 and nowallowed, which in turn is a continuation-in-part under 35 U.S.C. 120 ofcommonly assigned U.S. patent application Ser. No. 12/347,831, entitledAnchors and Method for Securing Suture to Bone, filed on Dec. 31, 2008and now allowed. U.S. patent application Ser. No. 12/485,878 also claimsthe benefit under 35 U.S.C. 119(e) of the filing date of ProvisionalU.S. Application Ser. No. 61/061,960, entitled Devices, Systems, andMethods for Material Fixation, filed on Jun. 16, 2008. Each of theseprior patent applications are expressly incorporated herein byreference, in their entirety.

BACKGROUND OF THE INVENTION

The present invention is generally related to the field of sutureanchors. There are many procedures, such as SLAP (Superior Labrum fromAnterior to Posterior) and Bankart lesion repairs, or reconstruction oflabral tissue to the glenoid rim, in which a surgeon needs to securetissue in close contact with bone. Often the bone surface is roughened,and when tissue is pulled into intimate contact, the body's healingresponse will fuse the tissue and bone together.

This procedure is often accomplished by implanting an anchor, pre-loadedwith a strand of suture, into a hole drilled in the bone at the desiredanchor location. One of the suture ends is then passed through the softtissue at the desired location, and the suture is secured to the anchorby tying a knot.

There are many suture anchor designs on the market today intended tosecure suture, which is passed through soft tissue, to bone. Most of theanchor designs rely on interference between external features on theanchor (barbs, ribs, ridges, etc.) and the hole to provide fixationstrength. A high amount of interference results in a large forcerequired to insert the anchor into the bone. These large insertionforces (often imparted by a hammer or mallet) can result in brokenanchors, broken insertion tools, or worse, damage to the bone itself. Animportant step in the procedure is adding tension to the suture to pullthe captured tissue into intimate contact with the bone. Many anchorscan change the tension in the suture during deployment, which requiresthe surgeon to estimate how much tension will be added during the finalinstallation step. This can result in under- or over-tensioning of thetissue against the bone. The final step of securing the suture andtissue—tying a knot—has been shown to be a common source of anchorfailure. It is also a step that requires a great deal of practice andskill by the surgeon and time during the procedure itself.

Since the knot is often problematic for the reasons stated above,several knotless designs have recently been developed. Some of these aredescribed below:

The Bioknotless™ anchor by DePuy Mitek is a simple anchor which isloaded with a loop of suture secured to the anchor with a knot. The loopis passed through the tissue, then the loop must be hooked in a grooveat the tip of the anchor. This step can be tedious and difficult,depending on the angle of approach to the hole. Finally, the anchor istapped into the hole in the bone. The final tension on the suture loopand attached tissue is controlled by the anchor insertion depth. Thisrequires the surgeon to drill a hole deep enough to achieve sufficienttension. If the bite of tissue through which suture is passed is smallerthan expected or achievable, the anchor may reach the bottom of the holebefore enough tension is placed on the tissue. This results in thetissue not being pulled firmly against the bone surface and may resultin inferior long-term repair strength. Depending on the angle ofapproach and the location on the bone (such as inferior on the glenoid),it may be impossible to drill a deep enough hole to achieve the desiredtension.

Arthrocare has developed the LabraLock P™ anchor. This two-part anchor,made from PEEK (Polyetheretherketone), secures two strands of suture(the strands which form the loop that is passed through the tissue)between the anchor and the bone, and the other two strands (the freeends of suture) between the anchor's inner shaft and the outer, tubeportion. The outer tube portion has barbs which secure the anchor in thebone via an interference fit.

The PushLock™ anchor, by Arthrex, is also a two-part anchor. The tip ofthe anchor has an eyelet through which the suture legs are loaded. Thistip is placed at the bottom of a hole drilled into the bone. At thispoint, the surgeon may adjust the tension on the suture, thereby pullingthe tissue closer to the surface of the bone. When the tension is deemedcorrect, the rear portion of the anchor is driven into the hole. Thisrear portion is a length of tube which has circumferential barbs on itsouter diameter which provide interference to anchor the device in thehole. Since the barbed portion of the anchor is a full cylinder, it canrequire a great deal of force to insert into a smaller diameter hole,especially in hard bone.

The ConMed Ultrafix Knotless Minimite™ anchor is a knotless anchor madeof metal, which many surgeons do not want to deploy within a joint. Ifthe anchor were to pull out of the bone, the metal could cause a greatdeal of damage rubbing against the articular surfaces—e.g. the humeralhead and glenoid.

Smith & Nephew has marketed the KINSA™ suture anchor. It is a knotlessdesign made of PEEK which is tapped into a pre-drilled hole in the bone.The anchor is preloaded with suture tied in a one-way sliding knotwithin the anchor body, which allows the surgeon to adjust the tensionafter the anchor has been deployed.

SUMMARY OF THE INVENTION

The anchor described in the current invention incorporates severalfeatures which make it simple and consistent for the surgeon to implant.In particular, the current designs allow the surgeon to adjust thetension on the suture strands, thus approximating the captured tissue tothe anchor location prior to securing the anchor and suture.Additionally, when the anchor is locked into the bone, the tension onthe suture and captured tissue does not change.

Another advantage of the current designs is that they eliminate the needfor the surgeon to tie a knot. The performance of the knot is dependentupon many factors—the skill of the surgeon, the type of suture material,the ease of access to the knot location, etc. Tying a secure knot oftenrequires several knots, such as a Duncan Loop backed up by alternatinghalf-hitches. Each of these must be pulled tight with a knot pusher tosecure them properly. Securing the suture between the anchor and bone ismuch less time consuming and less prone to surgeon error or variability.

More particularly, an anchoring system for securing suture to bone isprovided which comprises an implant including a distal tip having asuture securing portion, preferably a suture eyelet, and having externalsurface features for securing the implant within surrounding bone, andalso including a proximal member which is movable distally to engage thedistal tip and to fix the suture in place within the implant andrelative to the bone. The anchoring system further comprises an inserterwhich is removably connectable to a proximal end of the implant. Theproximal member preferably comprises a screw member having a centralbore. The inserter comprises an inserter tip which is configured toslide through the central bore of the screw member.

The inserter tip further comprises a threaded distal tip which isadapted to engage a corresponding threaded hole in a proximal end of thedistal tip. The threads in the threaded hole are left-handed, A handleportion is connected to a proximal end of the inserter. A suture channelis disposed on an external surface of the implant for permitting thesuture to slide freely along the external surface for tissue tensioning.These external surface features preferably comprise ribs, which arepreferably triangular-shaped. The inserter further comprises aninsertion sleeve for pushing the proximal member distally over theinserter tip. The inserter further comprises a handle.

The handle, in turn, preferably comprises a plurality of suture cleats,as well as a knob which is actuatable to engage the proximal screw tothe distal tip.

In another aspect of the invention, there is disclosed a method forsecuring suture to bone, which comprises steps of drilling a hole in adesired portion of bone at a desired procedural site, passing a strandof suture through a portion of soft tissue to be approximated to theportion of bone, and extending the free suture ends proximally from thesoft tissue. Additional inventive steps comprise loading the suture intoa distal tip of an anchor implant, using an inserter, on a distal end ofwhich is attached the distal tip, to manipulate the distal tip into thebone hole, and tensioning the suture to a desired level by pulling onthe free suture ends, after the distal tip is positioned in the bonehole. The free suture ends are then wrapped about a suture cleat on aninserter handle once the desired tension level is achieved. A proximalanchor component is engaged with the distal tip to lock the anchor inplace within the bone hole, and to lock the suture in place within theanchor. When the procedure is complete, the inserter is removed from theprocedural site.

An additional procedural step comprises a step of trimming the freesuture ends. Preferably, the loading step comprises placing the suturethrough a suture eyelet in the distal tip. The proximal anchor componentcomprises a screw with external threads, and the engaging step comprisesadvancing the proximal anchor component to the entrance of the honehole, then rotating the end of the inserter to screw the proximal anchorcomponent into the bone hole. The proximal anchor component is advancedby pushing it with an insertion sleeve.

In yet another aspect of the invention, there is disclosed a sutureanchoring system which comprises a suture anchor comprising a distal tipand a proximal screw, as well as an inserter which is removablyconnectable to a proximal end of the suture anchor. The distal tip andthe proximal screw are separate structural components which areengageable together to form the suture anchor. The proximal screwcomprises a central bore. The inserter comprises an inserter tip whichis configured to slide through the central bore of the proximal screw.

The inserter tip further comprises a threaded distal tip which isadapted to engage a corresponding threaded hole in a proximal end of thedistal tip. The threads in the threaded hole are left-handed.

A handle portion is connected to a proximal end of the inserter. Theinserter further comprises an insertion sleeve for pushing the proximalscrew distally over the inserter tip. The handle comprises a pluralityof suture cleats, as well as a knob which is actuatable to engage theproximal screw to the distal tip.

The invention, together with additional features and advantages thereof,may best be understood by reference to the following description takenin conjunction with the accompanying illustrative drawing.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a distal end view of one embodiment of a “suture first”suture-to-bone implantable anchor constructed in accordance with theprinciples of the present invention;

FIG. 2 is a view similar to FIG. 1 , after suture has been snared by theinventive device and pulled proximally through an eyelet in the implant;

FIG. 3 is a view similar to FIGS. 1 and 2 , showing the inventive devicebeing inserted into a drilled bone hole;

FIG. 4 is a view similar to FIG. 3 , illustrating the inventive deviceafter it has been advanced to a distal end of the bone hole;

FIG. 5 is a view similar to FIGS. 3 and 4 , illustrating the deviceafter the suture has been tensioned by the practitioner to approximatethe captured tissue to the anchor location;

FIG. 6A is a plan view illustrating an inserter for use with the implantof FIGS. 1-5 ;

FIG. 6B is a detail view of the portion denoted by circle B in FIG. 6A;

FIG. 6C is a detail view of the portion denoted by circle A in FIG. 6A;

FIG. 6D is a cross-sectional view taken along lines 6D-6D in FIG. 6C;

FIG. 7A is an isometric view of the insertion shaft forming a portion ofthe inserter illustrated in FIG. 6A;

FIG. 7B is a plan view of the insertion shaft of FIG. 7A;

FIG. 7C is a plan view similar to FIG. 7B, rotated approximately 90degrees;

FIG. 7D is a cross-sectional view taken along lines 7D-7D of FIG. 7B;

FIG. 7E is a cross-sectional view taken along lines 7E-7E of FIG. 7C;

FIG. 7F is a top end view of the inserter shown in FIG. 7B;

FIG. 7G is a top end view of the inserter shown in FIG. 7C;

FIG. 7H is a bottom end view of the inserter shown in FIG. 7B;

FIG. 8A is an isometric view of a mating screw used in connection withthe embodiment of FIG. 1 ;

FIG. 8B is a plan view of the screw of FIG. 8A;

FIG. 8C is a cross-sectional view taken along lines 8C-8C of FIG. 8B;

FIG. 9 is an exploded view of the suture anchor and screw of theembodiment of FIGS. 1-8C;

FIG. 10A is an isometric view of a modified embodiment of the inventiveimplant;

FIG. 10B is a plan view of the implant of FIG. 10A;

FIG. 10C is a plan view similar to FIG. 10B, rotated approximately 90degrees relative to FIG. 10B;

FIG. 10D is a cross-sectional view taken along the lines 10D-10D of FIG.10B;

FIG. 10E is a plan view similar to FIG. 10B, rotated approximately 180degrees relative to FIG. 10B;

FIG. 10F is a top view of the implant illustrated in FIG. 10C;

FIG. 11A is a plan view similar to FIG. 10E, after suture has beendeployed therein;

FIG. 11B is a cross-sectional view taken along lines 11B-11B of FIG.11A;

FIG. 11C is a top view of the implant illustrated in FIG. 11B;

FIG. 12 is a plan view of another modified embodiment of an inserter andsuture anchor constructed in accordance with the principles of thepresent invention;

FIG. 13A is an isometric view of the distal tip of the suture anchor ofFIG. 12 ;

FIG. 13B is a view similar to FIG. 13A illustrating the anchor loadedwith suture;

FIG. 14 is an isometric view showing the distal tip of the suture anchorof FIGS. 12-13B as it is inserted into a drilled hole (socket) in bone;

FIG. 15 is an isometric view similar to FIG. 14 , wherein the anchorcomponents have been engaged;

FIG. 16 is an isometric view similar to FIG. 15 , wherein the anchor hasbeen fully deployed and the inserter removed;

FIG. 17 is an exploded side view of the two components of the anchor ofthe inserter tip of FIG. 12 , prior to deployment with a bone socket;

FIG. 18 is a side view similar to FIG. 17 wherein the anchor componentsof the embodiment of FIG. 12 are fully deployed;

FIG. 19A is an isometric view of one component of the inventive anchorof FIG. 12 ;

FIG. 19B is a similar view to that of FIG. 19A, illustrating the othermajor component of the anchor of FIG. 12 ;

FIG. 20A is a top isometric view of the proximal wedge of the embodimentof FIGS. 12-19B;

FIG. 20B is a bottom isometric view of the proximal wedge of FIG. 20A;

FIG. 21 is an isometric view of the inserter distal end of theembodiment of FIGS. 12-20B;

FIG. 22 is an isometric view of the inserter handle of the embodiment ofFIGS. 12-20B;

FIG. 23A is a cross-sectional side view of a modified embodiment of theinserter tip shown in FIGS. 12-21 , with the wire lock in an unlockedposition;

FIG. 23B is a cross-sectional side view of the embodiment of FIG. 23A,wherein the wire lock is in a locked position;

FIG. 24 is an isometric view of still another modified embodiment of theinserter tip of FIGS. 12-21 ;

FIG. 25 is an isometric cross-sectional view of the inserter tip of FIG.24 ;

FIG. 26A is a side cross-sectional view of yet another modifiedembodiment of the inserter tip of FIGS. 12-21 , wherein the flex arm isin a locked position;

FIG. 26B is view similar to FIG. 26A, wherein the arm is in an unlockedposition;

FIG. 27 is an isometric view of still another embodiment of the insertertip of FIGS. 12-21 ;

FIG. 28 is a cross-sectional view of the distal portion of theembodiment of FIG. 27 ;

FIG. 29 is a plan view of another, presently preferred, embodiment of aninserter for installing a suture anchor;

FIG. 30 is an isometric view of components of the suture anchor loadedon the distal tip of the inserter of FIG. 29 ;

FIG. 31 is an isometric view similar to FIG. 30 , showing a length ofsuture loaded onto the suture anchor;

FIG. 32 is an isometric view showing the distal tip of the inserter ofFIG. 29 after it has been slid along the suture strands into anarthroscopic working space within a patient;

FIG. 33 is an isometric view similar to FIG. 32 , showing the deviceafter the suture has been tensioned and the proximal screw has beenadvanced into the working space;

FIG. 34 is an isometric view similar to FIG. 33 , showing the sutureanchor in place within the working space, with the inserter tool removedand the free ends of the suture trimmed flush;

FIG. 35 is an isometric view of the distal tip of the inserter of FIG.29 , shown in isolation;

FIG. 36 is an isometric view similar to FIG. 35 , showing e distal tipfrom the opposing side;

FIG. 37 is an isometric view of the proximal screw of the presentinvention, shown in isolation;

FIG. 38 is an isometric view similar to FIG. 37 , from an opposing side;

FIG. 39 is an isometric: view of the inserter tip of the presentinvention; and

FIG. 40 is an isometric view of e inserter handle of the presentinvention.

DESCRIPTION OF THE PREFERRED EMBODIMENT

Referring now more particularly to the drawings, there is shown in FIGS.1-5 the distal end of a “suture first” suture to bone implantableanchoring device 10. The device 10 comprises an inserter 12, and animplant 14 loaded on the tip of the inserter 12. Suture 16 is disposedalong the inserter 12, as shown in FIG. 1 , for example, and through theimplant 14, with a loop 18 of suture extending therefrom. This loop 18is the loop of suture which would extend through the tissue to beapproximated to the bone, which is not shown, for clarity. Also notshown in this figure is a suture snare that is used to pull the sutureloop 18 into a suture eyelet in the middle of the implant 14, which isillustrated and described below. The snare may comprise a loop ofnitinol wire or suture, insert molded into a plastic pull-tab (notshown) which may be mounted on the shaft of the inserter 12. Once thesuture strands are placed into the suture snare, the pull-tab is removedfrom the inserter shaft and pulled proximally to ensnare the suturestrands and pass them through the eyelet in the implant. FIG. 2illustrates the inserter 12 and implant 14 after the suture has beenpassed through the implant eyelet. In accordance with a method of theinvention, the inserter 12 of FIG. 1 is slid along the suture 16distally and through an arthroscopic portal into the patient's body, inthe vicinity of the desired procedural site. The distal tip of theimplant is then inserted into a hole or tunnel 20 (FIG. 3 ) which hasbeen pre-drilled in a selected bone portion 22, and advanced until it isflush with the bottom of the hole 20 (FIG. 4 ). At this point, thesurgeon can pull on the free ends of the suture 16, which have remainedoutside of the arthroscopic portal (not shown), to tension the suture 16and thereby approximate captured tissue (not shown) to the anchorlocation. The device after the suture has been tensioned by the surgeonto approximate the captured tissue to the anchor location is illustratedin FIG. 5 .

FIGS. 6A-6D illustrate an embodiment of a simple insertion device whichmay be used in conjunction with the device 10. It is noted that theimplant 14 may be comprised of a biocompatible material, such as PEEK.FIG. 6C illustrates the implant in its suture-loaded configuration,ready for insertion into the bone drill hole and ready for deployment.As shown in FIG. 6D, the implant further comprises a screw 24, which isretained only partially within the implant 14 prior to deployment. Anengagement tube 26 is also disposed within the implant 14. Its purposeis to tighten the screw 24, and to couple the screw and implant 14 tothe insertion device 12. The tip of the engagement tube 26 is threadedto engage with the top of the screw 24. The inserter or insertion device12 comprises an insertion shaft 28. The insertion shaft functions totransfer a load from the insertion device 12 to the top of the implant14, thereby allowing the implant 14 to be hammered or pushed into thedrill hole 20. The insertion shaft 28 engages with the engagement tube26 by means of a threaded engagement 30 between the insertion shaft 28and the engagement tube 26 at a proximal end of the inserter 12 (FIG. 6Band Detail B of FIG. 6A). The thread between the insertion shaft and theengagement tube is in a 1:1 ratio with the PEEK screw 24 in the implant,so that the travel distance of the PEEK screw 24 and the engagement tube26 remains the same. Moreover, the travel distance is adjustably limitedby the threaded portion 30 shown in FIG. 6B.

Proximal to the threaded portion 30, is a handle portion 32, forpermitting manipulation and rotation of the device 10, as desired.

There are two potential modes of removal of the insertion device 12 fromthe implant 14, after deployment. In one such mode, after deployment ofthe implant by tightening the screw 24, the screw can be purposelyover-tightened, thus breaking the screw 24 off from the implant 14.Testing has shown that the screw 24 does not need to be madespecifically “frangible” for this method to work repeatedly, astorsional stress are always the highest in the PEEK screw 24 at the tipof the engagement tube 26.

Another mode for removal assumes that after deployment or tightening ofthe screw 24, the frictional forces of the suture 16 against the screw24 are high enough to prevent the screw 24 from loosening while theengagement tube 26 is rotated in the anti-deployment direction to loosenits threads from the PEEK screw 24. Of course, other suitable removalmodes may be utilized as well.

FIGS. 7A-7H illustrate in greater detail constructional features of theimplant 14. In particular, the implant 14 comprises internal surfacetexturing 34 at a pinch point within the implant, for improving sutureretention after fixation. The internal surface texturing may comprisespikes, knurling, or other known biting surfaces of that nature.

A suture eyelet or cleat 36 is provided within the implant. The sutureloads through the eyelet with the use of a suture snare, as wasdescribed above. During deployment, the suture get pushed within thecleat, which bites into the suture for retention. A suture channel 38allows the suture to slide freely along the external walls of theimplant 14 for tissue tensioning. In practice, the implant 14 isinserted into the bone tunnel 20, and desired tension is achieved bymanually pulling on the suture strands. Once the desired tension isachieved, the screw 24 locks the suture in place.

An internal thread 40 is provided within the PEEK implant 14. The matingscrew 24 creates a pinch force, locking the suture into place aftertensioning. The thread also serves as a retention mechanism forattaching the implant and screw to the insertion device 12. A pluralityof frustoconical surfaces or barbs 42 serve to retain the implant andresist pullout from adjacent bone.

FIGS. 8A-8C illustrate in greater detail the mating screw 24. As notedabove, tightening of the screw within the implant 14 locks the sutureinto place by pinching it against the bottom of the anchor and also byforcing it into the suture cleats connected to the suture eyelet. Thebottom 44 of the screw 24 may be knurled, cupped, or pointed to increasethe pinching force that locks the suture into place.

FIG. 9 is an exploded view of the implant 14 and screw 24, shown, forclarity, without suture and not attached to the insertion device 12.

A modified embodiment of the implant 14 is illustrated in FIGS. 10A-11C.In this embodiment, rather than having the suture being pinched solelyat the bottom of the implant 14, this embodiment features one leg 16 aof the suture running on the external side of the implant, while theother leg 16 b of the suture remains inside of the implant to becompressed against the screw 24 and along the tapered edge of a suturecavity 46. The implant is threaded, as in the prior embodiment, butbecause of the tapered internal cavity 46 inside one half of theimplant, the thread is not fully circumferential. Instead, it extendsdownwardly along a “C” shaped screw portion 48. The PEEK screw 24 stillcouples the implant to the inserter, in the same manner as the device ofFIGS. 1-9 . The internal cavity is tapered to allow the suture to slidefreely for tensioning up until the point that the screw is tightenedfully. A single suture channel 50 permits the suture to slide freelythrough the suture eyelet 36, after placing the implant 14 and sutureinto the drill hole 20 in the bone 22. Upon tightening of the screw 24,the suture 16 is effectively squeezed along the internal tapered cavity46 and screw 24, thus locking the suture in place.

Returning again to a discussion of a method of use of the inventivedevice 10, once the proper tension is achieved, the suture ends can bewrapped around cleats on the inserter handle 32 to maintain the desiredtension. The surgeon then removes a safety pin from the inserter 12 androtates the main handle portion 32 clockwise while holding a smallinserter knob stationary. This drives the screw 24 inside the implanttowards a pinch point, pushing the suture strands 16 into suture cleats36 in the implant 14 while pinching the suture firmly at the insidebottom of the implant to prevent it from slipping. The handle is rotateduntil the proximal end of the screw (threaded inside the engagementtube) shears, releasing the inserter from the implant site. An alternatemethod of releasing the inserter would be to rotate the inserter handlecounter-clockwise at the end of the screw's travel, while holding thesmall knob stationary. At this point, the friction of the suture againstthe PEEK screw prevents the screw from unscrewing. However, since thehandle is rotated counter-clockwise, the inserter would unscrew itselffrom the end of the PEEK implant screw thus releasing it from the siteof implant.

Now with reference to FIG. 12 , another embodiment of an inventivesuture anchoring device 52 is illustrated. The device 52 is a simple toinsert suture anchor which permits adjustment of suture tension prior todeployment, does not change the tension on the suture (and, as a result,the captured tissue) when it is deployed, does not require a knot tosecure the suture, and does not require high insertion forces over theentire depth of insertion into the bone socket. The device 52 comprisesa distal tip 54, a proximal wedge 56, and an inserter 58, as well as ahandle 60. As shown in FIGS. 13A 16, the inserter 58 further comprisesan inserter tip 62. A suture eyelet 64 is disposed at a distal end ofthe distal tip 54. Suture 66 may be loaded onto the device 52, in amanner that will be described below.

Most anchors are supplied pre-loaded with suture passing through aneyelet in the anchor. Such a design is an “anchor first” design, whereinthe surgeon drills a hole in a desired location, installs the anchor inthe hole, passes one of the free ends of suture through the tissue, andthen ties a knot to secure the suture and attached tissue to the anchor.However, the present invention is a “suture first” approach. Again, thesurgeon, in a representative procedure performed in accordance with theinvention, drills a hole 68 in a desired portion of bone 70 (FIG. 14 ),in a selected anchoring location. Then, a strand of suture 66 is passedthrough the tissue (not shown) with the surgeon's choice of suturepassing tools. The free suture legs 66 a, 66 b are then brought out ofthe patient's body for loading into the suture anchor. FIG. 12 shows thesuture anchor components 54, 56 pre-loaded onto the disposable insertertool 58. The suture anchor comprises two separate parts, the distal tip54 and the proximal wedge 56, which engage and lock together whendeployed within the bone socket 68.

FIG. 13A shows a close-up of the suture anchor components loaded on theinserter tip 62. The suture 66 is shown loaded into the anchor in FIG.13B. The two free ends 16 a, 16 b of the suture 66 are passed throughthe eyelet 64 in the distal tip 54. This step can be aided by the use ofa nitinol wire snare or suture snare to pull the ends through theeyelet. The loop shown is the loop which passes through the tissue. Thetip of the inserter, with the anchor in place, is then slid down thesuture strands into the arthroscopic working space. The distal tip 54 isinserted to the bottom of the drilled hole or socket 68, as shown inFIG. 14 . At this point, the surgeon can pull on the free ends 66 a, 66b of the suture, which are still outside the patient's body, to addtension and approximate the captured tissue to the anchor location. Oncethe proper tension is achieved, the suture ends can be wrapped aroundsuture cleats 72 on the handle 60 to Maintain the desired tension.

Once the proper tension is achieved, the surgeon taps on the end of theinserter handle 60 to push the proximal wedge 56 into the hole 68, asshown in FIG. 15 . When the proximal wedge is fully seated, the twoanchor components 54, 56 lock together within the socket 68.

Finally, as shown in FIG. 16 , the inserter tool 58 is removed, and thefree ends of the suture are trimmed flush.

FIG. 17 illustrates a side view of the two components 54 and 56 of theanchor 52 on the inserter tip 62, prior to deployment within the bonesocket 68. The exterior surface of the anchor components comprises barbs74, although alternative surface features may also be employed forensuring a solid engagement between the anchor and the interior bonysurface of the hole 68.

FIG. 18 shows the two components 54, 56 of the anchor in a deployedstate. The proximal wedge 56 has been driven against the distal tip 54,locking the two pieces together with three sets of snap features 76. Theprimary mating surface 78 between the two components 54, 56 is at anangle with respect to the axial orientation of the respectivecomponents. This results in the components wedging apart and providinggreater interference when fully engaged in the bone hole 68.

FIGS. 19A and 19B illustrate details of the distal tip 54. The front ofthe distal tip contains the eyelet 64, through which the suture ends arepassed. The eyelet is closed, so that the suture legs 66 a and 66 bcannot come free of the anchor after they are loaded. The top surfaceincludes a Channel 80 to accept the inserter tip 62. In a preferreddesign, the channel 80 is hourglass-shaped to aid in holding the distaltip 54 onto the matching contour of the inserter tip 62, and to preventrotation of the components with respect to the inserter. The bottomsurface of the distal tip includes a suture channel 82 through which thesuture ends pass. This channel 82 allows room for the free suture legsto slide between the anchor and the bone socket when the distal tip isplaced at the bottom of the hole 68. When the anchor is deployed, thedistal tip is pressed against the side of the bone socket, reducing thesize of this channel and compressing the suture between the anchor andthe bone.

Two views of the proximal wedge 56 are shown in FIGS. 20A and 20B. Thiscomponent contains; the same hourglass-shaped channel 80 to hold thepart onto the inserter tip 62 and prevent rotation. There are alsocorresponding snap feature notches which engage with the snap features76 on the distal tip to lock the two parts together when deployed.

The distal end of the inserter 58, illustrated in FIG. 21 , includes twocomponents to deploy the anchor 10, The inserter tip 62 has an hourglassprofile 86. The hourglass shape helps to secure and prevent rotation ofthe anchor components on the tip. Just proximal to the tip is aninsertion sleeve 88. When the end of the inserter is tapped with amallet, the insertion sleeve 88 moves distally to drive the proximalwedge 56 into the hole 68 and engage with the distal tip 54.

The handle 60 of the inserter is shown in FIG. 22 . The distal end ofthe handle includes a set of suture cleats 72. After a proper suturetension has been achieved, the suture may be wrapped around the cleats72 to secure them and prevent further movement. The inserter handle 60is fixed relative to the hourglass-shaped inserter tip 62. At theproximal end of the handle 60 is a knob 90. The knob is fixed relativeto the insertion sleeve 88. When the knob 90 is tapped with a hammer, itdrives the insertion sleeve 88 and the proximal wedge 56 forwardly withrespect to the handle, which the surgeon is holding, and the distal tip54. The knob 90 moves flush with the end of the handle when the twoanchor components 54, 56 are fully engaged.

There are several variations from the above described embodiment ofFIGS. 12-22 which may be incorporated, if desired. For example, withrespect to the implant, the external holding features of the anchorcomponents (shown in the depicted embodiment as the circumferentialbarbs 74) could be a number of different shapes, depending upon desiredperformance and location of the anchor. The circumferential features maybe ridges, with equal angles on both the leading and trailing edges,especially on the distal tip 54. This could aid in preventing the distaltip from moving in either direction, distally or proximally, afterdeployment. The barbs may be interrupted to reduce insertion forces inhard bone or to encourage tissue ingrowth after insertion.

In addition, the blind hole in the distal tip could include featureswhich aid in holding the distal tip onto the inserter tip. Three ofthese potential variations are discussed below.

FIGS. 23A and 23B show a variation of the inserter tip 62 and implantwhich offers improved retention of the distal tip on the inserter tip.For this variation, a transverse hole 92 has been added to the distaltip, which intersects the hourglass-shaped blind hole. The inserter tipshaft has been modified to include a central hole down the center with aramp feature 94 at the distal end of the part. A wire 96 is locatedwithin this central hole. This position is the “unlocked” position, andthe inserter tip can be pulled to the right and out of the distal tip.When the wire is slid distally (to the left) within the inserter tip, itis diverted by the ramp feature and forced to extend proud of thesurface of the inserter tip, slightly into the transverse hole in thedistal tip (FIG. 23B). This is the “locked” position, which does notallow the inserter tip to be pulled to the right and out of the distaltip.

Another variation which serves the same purpose is shown in FIGS. 24 and25 . FIG. 24 shows a modification to the end of the inserter tip. Inthis design, the tip has a round cross-section where the distal tip isheld. Just proximal to the round section, the inserter tip has the samehourglass shape as shown in the afore described embodiments.

FIG. 25 shows a cross-section of the inserter tip, distal tip, andproximal wedge. As can be seen in this view, the most distal end of theinserter tip is threaded over a small portion of its length. The hole inthe distal tip into which the inserter tip fits includes a matingthreaded portion 98. This threaded portion serves to secure the distaltip to the end of the inserter tip. When the proximal wedge is deployed,it is pushed beyond the hourglass-shaped portion of the inserter tip.Once in the position shown, the inserter tip can be rotated to unscrewthe threads from the distal tip and removed.

Yet another variation of the inserter tip is shown in FIGS. 26A and 26B.The version illustrated requires two transverse holes in the distal tipwhich intersect the hourglass-shaped blind hole. This distal end of theinserter tip includes a central hole through which a wire can pass, athin slot 100 cut through the end, and two small bumps. As shown in FIG.26A, the wire is positioned at the end of the inserter tip. In thisposition, the distal tip cannot be pulled to the right and out of thedistal tip. When the wire is pulled to the right (FIG. 26B), the end ofthe inserter tip is allowed to flex at the thin slot 100, which flexesthe bumps out of the transverse holes and allows the inserter tip topull out of the distal tip.

FIGS. 27 and 28 illustrate another variation of a method of locking thedistal tip onto the end of the inserter tip. In this embodiment, theexternal, distal end of the inserter tip comprises the hourglass profileof prior embodiments. However, the inserter tip is cannulated, throughwhich an inner wire passes. The inner wire has a threaded portion 104which extends beyond the end of the inserter tip. This threaded portionthreads into an internally threaded hole in the distal tip. FIG. 28shows, specifically, a detailed cross-section of the distal tip,threaded inner wire, and inserter tip. The threads of the inner wire anddistal tip engage to secure the distal tip on the end of the assembly.To unlock, the inner wire is rotated to disengage the threads, and theinserter tip can be removed. The threaded portion of the inner wire canhave threads which are the same diameter as the inner wire, or,alternative, can have either a smaller or a larger diameter.

In FIG. 29 , there is shown another embodiment of a suture anchoringdevice 110. The suture anchor comprises two components, namely, a distaltip or implant 112, and a proximal screw 114. Components 112 and 114 arepre-loaded onto a disposable inserter tool 116.

The procedure for installing the suture anchor of the present inventionis similar to the procedure many surgeons are familiar with forinstalling existing suture anchors. Most anchors are supplied pre-loadedwith suture passing through an eyelet in the anchor. Such designs areknown as “anchor first designs”. The surgeon drills a hole in thedesired location, installs the anchor into the hole, passes one or bothof the free ends of suture through the tissue, and then ties a knot tosecure the suture and attached tissue to the anchor.

In contrast, the current invention is a “suture first” design. Again,the surgeon drills a hole in the bone at the desired anchoring location.For the next step, a strand of suture is passed through the desiredtissue with the surgeon's choice of suture passing devices. The freesuture legs are then brought outside the patient's body for loading intothe suture anchor.

FIG. 30 shows a close-up view of the suture anchor components 112 and114 loaded on an insert tip 118. Suture 120 is shown loaded into theanchor in FIG. 31 . The two free ends of the suture 120 are passedthrough an eyelet 122 in the distal tip 112. This step of threading thesuture 120 through the eyelet 122 can be aided by use of a nitinol wiresnare or suture snare to pull the ends through the eyelet. The sutureloop 124 shown in FIG. 31 is the loop which is passed through the tissueto be approximated (not shown).

Now with reference to FIG. 32 , the tip 118 of the inserter, with theanchor in place, is then slid down the suture strands 120 into thearthroscopic working space. The distal tip 112 is inserted to the bottomof a drilled hole or socket 126 in the bone 128, as shown in FIG. 32 .At this juncture, the surgeon may pull on the free ends of the suture120, which are still outside the body, to add tension and approximatethe captured tissue to the anchor location. Once the proper tension isachieved, the suture ends can be wrapped around suture cleats 130 onhandle 132 (FIG. 29 ) to maintain the desired tension.

Once the proper tension is achieved, the surgeon advances the proximalscrew 114 to the socket 126, in a manner to be discussed in more detailbelow, and rotates the end of the inserter handle to screw the proximalscrew 114 into the socket 126, as shown in FIG. 33 .

Finally, as shown in FIG. 34 , the inserter tool 116 is removed, and thefree ends of the suture 120 are trimmed flush to complete the procedure.

Now, with reference to FIGS. 35 and 36 , additional constructionaldetails of the distal tip 112 of the anchor are illustrated. The distaltip 112 comprises a transverse hole, or eyelet 134, through which thesuture ends are passed. The eyelet is closed so that the suture legscannot come free of the anchor after they are loaded. The rear surfaceof the distal tip 112 includes a threaded hole 136 (FIG. 36 ) foraccepting the threaded tip 138 of the inserter tip 118 (FIG. 39 ). In apreferred design, the threaded hole 136 has a left-hand thread, so asthe inserter tip 118 is rotated clockwise to drive the proximal screw114 into the bone socket 126, the distal tip 112 is unscrewed from theinserter tip 118.

The distal tip 112 also includes features, illustrated in FIGS. 35 and36 as triangular ribs 140, to prevent the tip from rotating in thesocket 126 as the inserter tip 118 is rotated. If the distal tip 112rotates when the inserter tip 118 turns, it might not unscrew from theinserter tip and it could wind the suture 120 within the socket. Theseanti-rotation features may take many alternative forms; such as ribs ofother cross-sections, posts, thicker walls on the sides of the distaltip 112, etc. The top and bottom features of the distal tip 112 includea suture channel 142 where the suture strands lie. These channels 142allow room for the suture strands to slide (to approximate the tissue tothe socket) between the anchor and the bone socket when the distal tipis placed at the bottom of the socket.

Two views of the proximal screw 114 are shown in FIGS. 37 and 38 . Thescrew has a thread profile 144 which is designed to optimize the holdingforce within the bone socket 126, securely compresses the suture 120against the walls of the bone socket, and does not grab or damage thesuture as it is inserted. The screw thread is also a double-start threadto reduce the number of turns required to fully insert the anchor. Theproximal screw 114 has a central bore 146, which is shown in thepreferred design as a square cross-section. The profile of this borecould alternatively be any shape which allows torque to be transmittedfrom the inserter tip 118 to the proximal screw 114—rectangular,triangular, hexagonal, etc.

The inserter tip 118 is shown in FIG. 39 . Three features of thisinserter tip assist in deploying the anchor. The inserter tip 118 has asquare profile which matches the internal bore 146 of the proximal screw114, so that the proximal screw 114 slides over the inserter tip, asillustrated. The square profile transmits torque from the driver to theproximal screw. The distal end of the inserter tip 118 includes thepreviously described threaded tip 138, for engaging with the internalthreaded hole 136 on the distal tip 112. The threads serve to hold thedistal tip 112 on the inserter tip 118, and to unscrew the distal tip asthe proximal screw is rotated and inserted, as described above. Justproximal to the inserter tip 118 is an insertion sleeve 148, When theend of the inserter is pushed forward, the insertion sleeve 148 movesdistally to drive the proximal screw to the entrance of the bone socket126 where the threads on the proximal screw 114 can engage the hole whenthe screw is rotated.

The handle 132 of the suture anchoring device 110 is shown in FIG. 40 .As noted previously, a distal end of the handle 132 comprises a set ofsuture cleats 130. After the proper suture tension has been achieved, asdiscussed above, the suture may be wrapped around the cleats to securethem and maintain tension on the suture strands. At the proximal end ofthe handle 132 is a knob 150. When the knob is pushed forward, it drivesthe insertion sleeve 148 and proximal screw 114 forward with respect tothe handle, which the surgeon is holding. The knob moves flush with theend of the handle when the proximal screw 114 is seated on the entranceof the bone socket 126. The knob is then rotated clockwise, whichrotates the inserter tip 118 and the proximal screw 114, driving thescrew 114 into the hole and securing the suture 120 and the distal tip112.

Accordingly, although an exemplary embodiment of the invention has beenshown and described, it is to be understood that all the terms usedherein are descriptive rather than limiting, and that many changes,modifications, and substitutions may be made by one having ordinaryskill in the art without departing from the spirit and scope of theinvention, which is to be limited only in accordance with the followingclaims.

What is claimed is:
 1. An anchoring system for securing suture to bone, comprising: an implant including an external surface and a distal tip, the distal tip including a suture securing portion structured to enable a suture to pass through the suture securing portion from one side to the opposite side, the external surface including external surface features for securing the implant within surrounding bone and a suture channel for permitting the suture to slide freely along the external surface for tissue tensioning; a proximal member which is movable distally to engage the distal tip and to fix the suture in place within the implant and relative to the bone; and an inserter extending from a proximal end to a distal end, the distal end of the inserter configured to be removably engageable with a proximal end of the implant, the inserter including an outer inserter shaft and an inner engagement tube extending within an inner lumen of the inserter shaft, wherein the engagement tube is rotatable relative to the inserter shaft to move the engagement tube distally within the inserter shaft, thereby moving the proximal member distally to fix the suture within the implant.
 2. The anchoring system as recited in claim 1, wherein the suture securing portion comprises a suture eyelet.
 3. The anchoring system as recited in claim 1, wherein the proximal member comprises a screw member.
 4. The anchoring system as recited in claim 3, wherein the implant includes a threaded internal surface structured to engage with a threaded external surface of the screw member.
 5. The anchoring system as recited in claim 1, wherein the inserter includes a handle portion disposed at the proximal end thereof.
 6. The anchoring system as recited in claim 5, wherein the handle portion includes a knob which is actuatable to engage the proximal member to the distal tip of the implant.
 7. The anchoring system as recited in claim 1, wherein the external surface features comprise ribs.
 8. The anchoring system as recited in claim 7, wherein the ribs are triangular-shaped.
 9. The anchoring system as recited in claim 1, wherein the inserter includes a plurality of suture cleats.
 10. The anchoring system as recited in claim 1, wherein the proximal member is comprised of a biocompatible material.
 11. The anchoring system as recited in claim 10, wherein the biocompatible material comprises PEEK.
 12. The anchoring system as recited in claim 1, wherein the implant includes internal surface texturing for improving suture retention after fixation.
 13. The anchoring system as recited in claim 12, wherein the internal surface texturing comprises spikes or knurling.
 14. The anchoring system as recited in claim 1, wherein the engagement tube is structured to engage with a proximal end of the proximal member.
 15. An anchoring system for securing suture to bone, comprising: a distal member including an external surface and a suture securing portion structured to enable a suture to pass through the suture securing portion from one side to the opposite side, the external surface including one or more external surface features for securing the distal member within surrounding bone and a suture channel for permitting the suture to slide along the external surface for tissue tensioning; a proximal member configured to engage the distal member, the proximal member being movable distally to fix the suture in place within the distal member and relative to the bone; and an inserter extending from a proximal end to a distal end, the distal end of the inserter configured to removably engage with a proximal end of the distal member, the inserter including an inserter shaft and an engagement tube rotatable relative to the inserter shaft, wherein a distal end of the engagement tube includes an internally threaded surface engageable with an externally threaded surface of the proximal member.
 16. The anchoring system as recited in claim 15, wherein the distal member includes a distal tip portion, and wherein the suture securing portion is located at the distal tip portion.
 17. The anchoring system as recited in claim 16, wherein the suture securing portion comprises a suture eyelet.
 18. The anchoring system as recited in claim 15, wherein the distal member includes a threaded internal surface structured to engage with the externally threaded surface of the proximal member.
 19. An anchoring system for securing suture to bone, comprising: an implant including an external surface and a distal tip, the distal tip including a suture securing portion structured to enable a suture to pass through the suture securing portion from one side to the opposite side, the external surface including one or more external surface features for securing the implant within surrounding bone and a suture channel for permitting the suture to slide along the external surface for tissue tensioning; a proximal member which is movable distally to engage the distal tip and to fix the suture in place within the implant and relative to the bone; and an inserter extending along a longitudinal inserter axis and having a distal end that is removably engageable with a proximal end of the implant, the inserter including a handle portion, a knob disposed at a proximal end of the handle portion, an outer inserter shaft and an inner engagement tube extending within an inner lumen of the inserter shaft, wherein the knob is rotatable relative to the handle portion and about the longitudinal inserter axis to rotate the engagement tube relative to the inserter shaft and to move the engagement tube distally within the inserter shaft, thereby moving the proximal member distally to fix the suture within the implant. 